Oscillating stairs



Jan. 5, 1954 A. M. GEORGIEV ETAL OSCILLATING STAIRS Filed July l2, 1950 5 Sheets-Sheet l MVS-Afro@ y MGM Jan. 5, 1954 A. M. GEoRc-:n-:v ETAL 2,664,990

OSCILLATING STAIRS Filed July 12, 195o 5 sheets-sheet s O xQ 72 36 s 73 0 if z 2 l a4 f4, \f 74 3g Jan. 5, 1954 A. M. GEORGIEV ET AL 2,664,990

OSCILLATING STAIRS Filed July l2, 1950 5 Sheets-Sheet 4 Eo/mea J ,6A WGOA/ Jan. 5, 1954 A. M. GEORGIEV ET AL OSCILLATING STAIRS Filed July 12, 195o 5 Sheets-Sheet 5 A1. sxA ,vase

X 5cm/deo JBA WSO/V /A/VE-A/To/e f7. @foes/EV C- ML Patented Jan. 5, 1954 'OFF 2,664,990 l"os'o''Iiimitunter ySTAIRS 4Alexander Michael G'edrziev rlieonaril J. Rawson, Dayton, 'Ohio Appiiesvieneoiyiz, issogserm matti Thi'sinvention aperta-ins to lifting equipment =for transporting a floadfromione level to another .by a plurality of increments totaling :the `distance between levels. When the load iis-a -humam being, he may be transported Afrom one level to another by `a lsuccession of easy stages Ywith minimum effort. The mechanized stairway will fbe Ause-ful in every home hav-ingtwo o r more floors 'and `w-ill i,be a convenient piece -of equipment `for :every person. A particular adapted for the .home installation is its usage outdoors, .such asfor Vlifting ,a person or load from Athe .street level .tothe-house level. The conventional elevators,` escalators .and sliding chairs are not usable in such applications. While not designed with that in mind theequipment is particularly adapted to persons suffering from fatigue or illness whereby they may ascend or descend from one level to another withv .n'o

i7 claim. (cites-416i more effort than Walking on a level floor. lWhile the mechanized stair can also be used :for descent its primary purpose `fis to ease and facilitate V a person or load in making ascent. When the load is an inanimate object such as a crate, lugbo'x or barrel, it nay vhe start'ed 'at .the lowest flevel whereupon it 'will be transported from lene level to another by a succession of lifts and self-"shifting movements. K l y y A lThis is accomplished by alterations of a conlventional stairway to incorporate a 'set of movable steps, `or part rof each step may be movable, "to be Adriven Yby a power 'source 'for transporting the load from one level to another. The movable steps maybe individually actuated, or they may be actuated in gangs or groups. Suitable .con-

trol elements actuated from a point or A'points f i `convenient t'o the stairway 'make rit 'possible to start, stop and regulate the stair movement.

The broad deiinition for the invention is: 'a

'mechanized equipment that moves "a loa'd from one level to another stepwise'thatis tosay, lifts a load through a series of upward movements or upward and forward movements, efect'ed by an external power means, as that of an electric motor, 'an hydraulic or pneuniatie 'drive or 'the like.

The amplitude of oscillation (in the case 'of inotion at lan incline) 'to Iloe the listancebetween two similar points of 'two adjacent steps, multifpled by an integer. 7The individual Steps 'may Abe raised and lowered one by one in propei' 'sequence, i. e., rst the .lowest Step, then the one above it and soon.

The raising and lowering of the individual steps 'can be effected 'bynieohanieal means driven by a suitable source of power, using pistons and cylinders, 'eccentrics orthe like; or the movement may be effected by electric means using soleneids or motors; -or vthe movement may be effected 'by means of llu'id pressure (hydraulic or pneumatic) 1vand 'a collapsible chamben such as lafpi's'ton and cylinder bellows, Sylphon or other closed coli-1- partment. While fthe Ydrawiirigs and description 'particularly r'show and describe a liquid "medium as the motivating means for 'the v`"flui'z'i pressure system, which necessitates 'a return circuit, the use of 'compressed air Iin place of liquid simplifies the `conduit arrangement, since no provisions have to 'be made for return jo'f the 'ilu-id. After it lllas performed the 'selected function it maybe -exhausted to the atmosphere. Application "of 'the driving power 'for the individually-actuated 5steps may Abe by personal ls'eleiition for ieach step,-su`c`h 'as loy actuating a switch or 'valve when stepping upon one of the 4step treads, 'which gives a selected 'speed of progress, or lthe `driving power may 'be 'applied automatically "by nne step factu- *ating a'yalvejor switch vas it `:I'iears the end 'o'f its movement. Oh the other hand, the application Aof -`driving power may 4be controlled through the 'o1'aeration "of Aa cycling unit "that progressively applies kthe step actuating 'force to fthe rst "step 'and "then'to the neiitiuntil the whol'e set of steps have been moved.

"Iheraisi'ng` 'and lowering jof 'the gang of Isteps "as a junit 'can be effected lby any of th alcove mentionedmean's and appropriate linkage 'for powering the individually Aactuated steps. 'The Acontrol in any case may take the form voif 'a 'valve or *switch located `4attire lhead and foot /o'f the stairway somewhat asa three-Way switch remotely contrcllin'gan electric light, 'or by *a Single A'control valve or switch opera-ble Vfrom veither the head or foot of the stairs or -at any point :along fthe'r'u'n "off the `stair structure. The `conytr'olvalve or :switch A'may be fitted with a member ,aetuata'ble 'from -lany poin't Aalong th'e stairway, forrinstane 'a lever andca'ble `or other linkage. The preferred form of 4equipment 'is existent in the reciprocating' gang stairway and 'is specifically illustrated 'and l"zlescrloed "herei'n,y and necessitates 'only 'one moving unit with a 'single control. A valuable advantage "of the 'equipment is the safety Ifeature. No part of lthe equipment is lifted high- 'er than the height `of a conventional 'step 'or from one step level to another, and lconsequently ne part 'of the equipment "can drop more than the height of a 'step of 'the system. kcontrasted with elevators and vthe vlike where a 'fall may, and has been 'experienced of one or more -loors, themoving vsta'ir'way is far less hazardous. There are a minimum "of moving parts in `the equip-k ment and the motions are simple, causing little wear. Contrasted with the escalator, its nearest relative, the reciprocating stairway is less expensive to install and maintain. The escalator is complicated to build and install, and there are a multiplicity of moving parts experiencing considerable wear and frequent replacement. Also the escalator needs additional space for the returning portions of the step conveying conveyor.

The reciprocating stairway has the unique feature of permitting an individual to stop his ascent or descent at any point of the transfer and return to the starting point without experiencing any inconvenience. Contrasted with this, a person using an elevator must usually continue to the next floor before he can return. In the case of an escalator the person using it can stop and return to the starting point only after reaching the other floor, or by Walking down the upward moving stairway. Also, a person using the reciprocating stairway may pause at any point or step level, and not return to the starting point, but resume the trip to the object level at his will. That usually cannot be done with the moving elevator or escalator.

The reciprocating stairway, wherein the step movement is confined to the vertical, is adapted to superimpose or overlay relation to one side of the original and existing installation, and when operated moves the load vertically from one level to the next requiring movement of the load forward enough and sideways to place it on the tread of the next step. The vertical movable type of reciprocating stairway may be adapted to an angling, winding or spiral stairway, since the guides provide the correct up and down movement. In stairways of complicated design, such as complicated bends, simplification may justify skipping or omitting one or more steps. However, the discontinuity of the movable portion is practicable. In such cases the ascending person will have to lift himself by his own power only a step or two. That amounts to only a slight inconvenience, which however, may generally simplify the construction of the equipment. Where the steps are individually reciprocated and each embodies control means for actuating the step, the equipment is suitable for transporting inanimate objects, especially if the load, that is the inanimate object, can coast upon the treads of the steps which have an incline of a few degrees downward in the direction of the horizontal travel. To spread the usage of that type of equipment the treads of the inclined steps may incorporate the rollers that support the load and permit it to coast onto the adjacent step when moved to the new level.

In some cases it is advantageous and less costly to move the reciprocating gang of steps along the slope of an incline instead of vertically. However the vertically moving gang is more adaptable to existing stairways and to angled or spiral stairways. When a faster and smoother climbing rate is desired, both portions of the steps, or two parallel portions of the stairway can be made to reciprocate at the same time but moving in opposite directions, i. e., while one is traveling upward the second is traveling downward, both reversing in movement at the same time. The double action is adaptable to both types of reciprocating stairways, whether it be the vertical or the inclined type.

A particularly suitable type of reciprocating gang steps adapted for portability is the mechanized ladder which has a movable gang of steps slidably mounted beside the conventional set of steps. The driving unit for that structure may be an electric motor with gear reduction and linkage for reciprocating the movable section the distance between two similar points of adjacent steps along the fixed set of steps. An extension cord then provides for connecting the power unit with a convenient source of electricity. Where the mechanized ladder is mounted on a fire truck or a utility service truck, the reciprocating portion may be driven by fluid pressure developed from the truck power plant. This type of equipment is very desirable with lire apparatus where firemen with heavy clothing are often required to carry equipment up and down a long flight of steps. Frequently, firemen are called upon to rescue persons from upper floors of a building. The descent is made less hazardous, and with less fatigue with the mechanized ladder.

Other objects and advantages will be in part evident and in part pointed out in the following description taken in connection with the accompanying illustrative drawings.

In the drawings wherein like numerals refer to like parts through the several views,

Fig. 1 is a fragmentary view in perspective showing schematically one form of our improved stairway for conveying a person from one floor level to another, by means of one movable flight and one fixed flight of steps.

Fig. 2 is a similar view of another form of our improved stairway wherein two movable flights arte operated for transporting a person at a faster ra e.

Fig. 3 is a view similar to Fig. 2, but showing the double flight of movable steps in a reversed position, or at the other end of the range of reciprocation.

Fig. 4 is a schematic view in side elevation of our improved stairway where the entire gang of steps is reciprocated vertically by one type of power device.

Fig. 5 is an elevational view showing schematically how the invention is applied to a motorized ladder.

Fig. 6 is an installation View in perspective showing our favored type of construction where the movable gang of steps is movable along an incline, one wall of the supporting structure having been removed for purposes of illustration.

Fig. '7 is a transverse sectional view substantially as indicated by the line and arrows 'l-'l of Fig. 6.

Fig. 8 is a longitudinal sectional view through the improved stairway substantially as indicated by the line and arrows 8-8 of Fig. 6, the view being taken through the movable section of stairs or steps and showing the power means for operating the movable steps.

Fig. 9 is an underneath view of the stairway shown in Fig. 8, substantially as indicated by the arrow 8.

Fig. 10 is a sectional view of a modified safety feature.

Fig. 11 is a fragmentary view in section showing details of the control apparatus for starting and stopping the movable portion of the steps substantially as indicated by the lines and arrows I I-II of Figs. 8 and l2.

Fig. 12 is an elevational View of the same substantially as indicated by the arrow I2 in Fig. 11,

Figs. 13 and 14 are details of the power control device.

Fig. 15 is a fragmentary view, showing in side .elevationfan alternative means ifm-:actuating the movable portion .of four .improved stairway..

Fig. 1:6 is a fragmentary -fview in elevation illustrating :schematically one itype I`of individually movable step. k

Fig. 17 is `a `sectiomtl view through the .same substantially as indicated by the line 4`and aarrows I'I-I'I of Fig. 16.

Fig. 18 is :a sectional view of .-a control valve for individually actuating .smglefsteps Operated by fluid pressure.

Fig. 19 is a sectional viewfof individually -operated steps .'for transporting inanimate loads.

With .reference .to the drawings, :and first Awith respect to the reciprocating `gang of steps. as shown in Figs. l .to 3 inclusive, 30 indicates `a string of iixedsteps 1,3, 5 and 1 connected by the usual risers and all supported yby :stringere 32 yone vof which is shown in Fig. 1. A :reciprocatable .string .of steps l:34 :has .steps .62, 4, 6 and Il .connected by the usual risers and .supported `by stringere 36. In Fig. 1 the movable :string tof .steps .34 is actuated :by a powerdevice 38 having cranks 40 and pitmans 42j which when ractuated cause the movable string of steps 34 .to reciprocate between limits 4along the extent of the fixed string 3i). The ran-ge of movement is the slant length .of distance between :similar points v`on two adjacent steps. In Fig. -1 the movable ,string .34 is in the .lower position Where step -4 islined up level withstep I., vand .when moved -to the other limit the step 4 is .lined up with iixed step `il.

In Figs. 2 and 3 thereare .two movable'strings .of steps which are marked 3411 for 4.the left hand section and 34B, for the right-hand section. The steps aresimilarly'connected by the conventional risers and supported by like stringere which yare pivotally connected .-by pitmans 42L and 42B. .actuated by cranks -40L and 40Rdriven by the power device 38,. The cranks 4IlL and 4BR yin Figs. 2 and 3 are .disposed 1801degreesapart1so that as they are driven by the power ,device 38, the two sections are moved in opposite directions. In Fig. 2 the stringof steps \34Lis at the lower limit while the stringi34R. at its upper limit, so that steps 2, 4 and 6 .are `level with steps 3, .5 and i respectively. 4In Fig. 3 the string 34L is at the upper limit with 4thestring 34H, :at the down limit. The steps `4, E vand18 are there level with steps I, 3 and 5. `Aspecific construction of the movably inclined .single gang is shown in Figs. 6 to 14 inclusive, described with `i-espectto an actual installation. Y

The xed string of steps 39 is secured to a wall 44 and extends 'between floors rI and 281by means of stringere appropriately notched to vunite .with the step risers 46 and treads 48 as shown 4'in Figs. 6 and 8. Thisfstring of steps made up of the treads 48 and the risers 46 ymake up the odd numbered steps 3; 5, 1, 9, .I I, I3, 15, ITI, I9, 2I, '23 and 25, the last'being levelor flush with the upper iioor level 28. It is adaptable tothe conventional means of traveling between floors. A movable string of steps 34 also .movably extends between the floors I and 28, being .made up of treads and risers as in the xed string 30 to provide the even numbered steps2, 4, 6, B, I0, I2, I4, 16,18, 2t, 2'2 and 24. These .steps .are mounted on stringers 36 inlike mannerto the `xed string 39, and the stringers 36 .areiitted withvchannels 50 opening outwardlyto receive rollers 52 secured to rigid structure of the building Asuch `as the wall member 54and the adjacent stringer ,32 of thexed string .of steps. The channels and rollers provide guideways for lthe movable string of yslant length lof the steps M .so -thatit may be `reciprocated :along the :stairway parallel `with fthe xed M y Movement rvor reciprocation of string .of steps 34 is accomplished by zt-he pitmans forlinks 42 attached to the .stringers 3.6 iat lvand `connecting with ithe cranks 48 of the power 38 yas .shown in .Figs -8 .and 9. The power device .illustrated comprises a gear Ireduction between .a rpulley .156 .and .the prank-shaft 58. .An electric motor 68 mounted'on a ibase 62 .is beltedor otherwise geared tothe pulley 56 by a belt ver chain .54. The gear .reduction and the -motor `are ymounted son 1a frame-work 66 :suitably disposed beneath :the :sta-irs for coupling fof Athe cranks and A.pitmans with thestringers of the imovableportion .of .the stairs. The .framework `withiits gear ,reduction and motor may fbegassembled as -a ,complete so that it may be moved .into place .beneath the .stairway :and secured .to the door `cfa closet, or itinaybe slung or supported in an inclined position as .shown in Fig. v.8in which position it will .give amplehead .room for a second iiight V.beneath and leading to a lower oor.

f Safety means are incorporated at Leach end of the movable .set-of steps so that .a person will not .stumble .over .an unexpected portion or .get his foot caught in any opening while the .stairs are moving. The y.top step, 26 of themovable .section as .shown in Figs. ..6 and f8, is mounted .on aipair of rails 68 each carryingchanne1 member 1 9 Vengaging rollers 12 mounted -on .horizontal .door .joists 'I3 supporting the floor .23. Thus the step 26 is capable of sliding horizontally beneath .the `floor 28 as the step 24 :is raised tothe level 4lof step .2-5. .Means are provided, including a spring,

weight or linkage, effecting the return slide of the step `26 :forward es the movable Ystring moves downward. With respect to the lowest movable .step 2, 4the stringers .36 are extended downwardly to be covered by an apron 14 which .slants tothe same degree and `direction as theinclination of thestringof steps. When the-steps aremoved to the upperpositon, the apron will cover any-openfingleft in the door `I bythe moving-step A2, somewhat as shown yinthe lower Apart'of Fig. 10. As shown in Eig. 7 a filler vpiece `36a is secured 'to lthe side-of the Stringer 36 tofill in the thickness .of the channel 5I) and roller 52 between the .two .sectionsof steps. That prevents a-.personejgetting .his .foot caught .between vthe proximate ends of :the fixed v'steps and the `movable steps when `the .stairway is operating.

The ,rest position of the movablestring-.ofrsteps in Figs. 6 ,and 8 isin the down position where Athe movable step 2 is iiush with the lowex` door I, and -wherethe'safety'step 26is projected forward `lio ali-gn with the .fxed step 25 4and the upper door leve1f28. In `Fig. 10, amodicationof the safety measures is shown Vfor keach Vend of the vmovable string .of steps. The apron 'Mat `the flower=end of the `rnovablezsteps ishere joined .to .the lfront edge of lmovablesstepl instead of to the front edgeof step 2 vas in Fig. 6. At the :upper end of 4the rmovable Vstring .step 26 ltelescopes fover an apron 16 supported by the iioor joists I3 so that it yslants downward :from the .front edge ofthe iioor 28. When .the movable string Aof steps in Fig. 10 slides from `the upward ory rest position as shown to the lower position, the apron 'I4 at the 'lower end of the steps will disappear while theupper apron 'I6 will 'be :exposed bythe :downward-movement lof "step y26. Thus, in neither instance 'can apersonplace hisfoot inr'suchaposition that'it winne/.caught between .relatively movable parts of the equipment. All potential openings while the movable stairway is at rest are covered. and are kept covered while moving until a position is reached by the movable steps that is proper for stepping on for travel.

Control of the power device for starting and stopping the movement of the reciprocating gang of steps is accomplished by the switch 11 and controller 19 shown in Figs. 11 to 14 where a mercury bulb circuit closer 80 is mounted in a pivoting bracket 82 oscillatable about a pin 84 carried by a slide bar 86, so as to be moved into an obstructing and into a free position with respect to some movable part of the sliding stairway. A spring 88 wound around the pivot pin 84, engages the bracket 82 and an anchor post 90 to urgethe switch and bracket to thehorizontal position engaging a stop pin 9| as shown in Fig. 13, where a roller S2 carried by the bracket 82 is disposed in the path of the moving part of the stairway. The bar 86 has a pair of slots 94 arranged along the length thereof through which screws or the like 96 extend loosely to thread into a iixed part 91 mounted on the underside of fixed stringers 32 so that the bar may slide toward and away from the movable string of steps as limited by the slots and screws. Fixed to one of the screws 96 there is a clip 99 providing an anchorage for a coil spring 88 that is attached at the other end to the bar 80 which spring normally moves the bar 86 toward the moving part of the stairway as shown in Fig. 11.

A cord or cable attached to the bar 86 trains over a pulley |02 within the wall 44 and then trains over a second pulley |04 to return through the wall 44 and attach to an oscillatable lever |06 which is operable by hand to control movement of the stairway. The lever |06 is pivoted in the bracket |08 of the hand rail H0, and is coupled with a control bar H2 extending the length of the handrail so that the control lever may be actuated at any point along the extent of the stairway. Other brackets |08 support the control bar and hand rail along the slant length of the stairway as shown in Figs. 6 and 8, where along with Fig. 11 it is apparent that pulling the control bar |2 away from the wall 44 and downward toward the hand rail H0, moves the control switch 11 disengaging any part of the movable string of steps. That permits the switch bulb 80 to oscillate to a horizontal position so that its contact points I4 and H6 will be bridged by the mercury mass H8. The contact points H4 and H6 are joined to conductors |20 and |22 respectively, communicating with one side of the motor 60 and |22 leading to a current source not shown. A conductor |24 connects the other side of the motor with the current source. Thus, the switch 11 controls the flow of current to the motor 60 for operating the movable section of the stairs, When the mercury mass H8 bridges the contact points H4 and H6 the motor 60 is energized and drives the power device 38 so that the movable gang of steps 34 slides up and down as guided by the channels and rollers 52.

To stop movement of the steps, the control bar H2 is pushed toward the wall 44 at any point along its length which permits the switch 11 to be moved into the path of the movable section of stairs. It is desirable that the moving section of steps always stop in the same position, and in such a position that no hazardous traps be left to endanger a person when approaching the stairway. The control switch 1T is therefore mounted 8 in a position and attitude suitable to be tilted to the circuit open condition when the moving stairway has reached the preferred rest position, such as at the end of the downward travel shown in Figs. 6 and 8, such as at the end of the upward travel in Fig. 10. As shown in Figs. 11 to 14 inclusive, the switch is mounted in a position and attitude to be tilted to circuit open condition by some part of an upwardly moving stair section such as shown in Fig. 10.

To be suitable for tilting to circuit open condition by some part of a downwardly moving stair section, suitable for control of the structure shown in Figs. 6 and 8, it is to be understood that the switch structure 11 of Figs. 13 and 14 would be mounted in inverted position, so that when engaged by the moving stair section it would be tilted downwardly to the circuit open position. That might be done without change of structure by removing and turning over the switch bracket 82. The switch and bracket are then assembled on the support in inverted relation from that shown in Fig. 14 so that it may pivot on pin 90 and have the spring 88 engage the pin 84 to urge the bracket upwardly against the stop pin 9 |a. In that attitude, the horizontal position of the bulb closes the motor circuit and the downward tilted position opens the motor circuit, which is effected by the downward moving section of the steps. In some types of mercury bulb switches it may be necessary to reverse the bulb with respect to the bracket so that the proper circuit relation can be obtained. In either instance, if the switch 11 is moved against the movable section while it is moving away from the rest position, the bulb will not be tilted because the relative movement of the stair section is such as to bias the bracket 82 against the stop pin 9| or Sia, as the case may be. The moving part of the stairs soon disengages the roller 92 and leaves the bracket 82 in the horizontal position and under the urge of the springs 82 and 98 somewhat as shown in Fig. 13.

Reverse movement of the stairway, that is movement toward the rest position will engage the bracket and eventually tilt the bulb 80 to the circuit open position at the proper instant to stop movement of the stair section in the desired rest position. Fig. 14 shows the switch in open circuit position when installed for control of a moving stairway having a rest position at the upper end of the stroke, in the nature of that shown in Fig. 10. Actuation of the control bar H2 for starting the movement of the stairs of elther type, acts to pull the bar 86 and the switch that it supports away from the stair Stringer, to the extent limited by the slots 94 which allows the bracket 82 to pivot to the horizontal position under the influence of the spring 88 despite the rest position of the movable section of steps. In the horizontal position of the bracket the switch 'H completes an electrical circuit through the motor 60 over the power leads |20, |22 and |24 and the power device drives the movable part oi the stairway. Obviously, the switch structure l1 and its actuating means may be adapted for the control of any type of moving stairway, it being only necessary to movably mount it so that it is out of the path of some moving part of the structure while the stair or step movement is desired and so that it is in the path of some moving part of the structure when it is desired to stop the stair or lstep movement. Other means than the described switch may be used for lining up the steps m the rest position, and may include photo-electric `cells rand relays, :with-perhaps the inclusion o! motor brakes. On ythe .other `hand',-the electric motor 60 may incorporate or be Ifitted A.with an electromagnetic brake Ito facilitate stopping the stairs when the two sectionsA are Ain the .desired alignment.

In Fig. -15 the movable flight -34 is actu-ated by a 4power device 33 of modified form. VIt may embody a piston and cylinder 4|26 mounted on a fixed support 428 and have its piston rod .|39 attached to a lbracket |32 carried by one of the stringers 36. Conduits |34 and |36 connect with opposite sides of the piston and leadto a pump and cycling unit |38 driven by a motor or the like 60 under control of the switch 1`|.I VWhen the pump and cycli-ng Vunit`| 38 are operating thestair section 34 is caused `lto slide up and down along the incline the extent of travel between two adjacent lstep levels such that thebrvacket |32 moves from -the solid line position to the dotted Yline position indicated a-t |32c. AIn that raised `position the step l2 will be Von a level with step 3 asshown by dotted lines. `Theother steps ,of the movable section will be raised an equal amount. As the fluid medium is delivered by the pump and cycling unit through the conduit ,|34 to project the piston, the conduit |36 returns the iluid medium in front of the piston to the pump and cycling unit, or to a reservoir connected with it.

As the piston reaches the limit .of its projected stroke. the oveline unit driven lov the motor reverses the ilow through the conduits 34 and |36 to retract the piston to the full line position. When the piston ,reaches the end of the ,inward stroke the oyoline unit with 4its Ipiloot seein reverses the flow and ,again proj-sots the piston outward. Wholi reversals v.o onolrlile so ylons as the switch ll Vis eloseol. When the .swltoll is moved into the path of some moving part of Vtlmstairway it is .tilted to a circuit open condition which stops the movable stairway in the rest position. Ontlle other hand, the power r device 38 might well .be an electrical device, or a mechanical unit driven by an electrical device, and might include `an actuator of VVthe ball serevv ,and .out .type .usesl ill aircraft for raising `and lowering landing gear and moving control surfeoes beine driven .by reversible electric motors with limit switches determining the extent `and -directionof travel,

The reciprocating gang type of steps is further illustrated in jliig. as having its embodiment in a 'ladder of portable construction to be o arried around, or mounted on a truck for transportation. The xed string of steps 30 comprises rails |35 and |40 spanned by rungs |42 providing therelatively fixed steps l, 3,5, 1, 9, Il, "I3, |5,'v|.1 and 4lg). A-third rail |46 in parallel spacedrelation to the ladder rail I4 forms a guide way for the sliding section of steps 34 which consists oferails |415 and |48 connected by rungs |50 forming the steps 2, 4,6, 8, I0, I2, I4, I G, |3 and 20. 'llieladderiraiirs |38, |49 and |44 are secured lto a Vbase -m loer |52 which carries a suitable power device 3g providing va crank 40 and'pitrnan A4 2 driyingly connected to the rung forming lthe lstep 42, of the movable stringrof steps. When the power device is operated the movable section 34 is vvcaused to slide up and down along the guides |49 v,and ,4.4.

One structurel ,form of the vertloelly .movable gang type of steps .that is suitable .for superimf posing over one end Iof lan existing stairway, `isshown in Fig. 4. The movable 'gang K34 4.is y suitably disposed within appropriate suislesifor ver.- tioal movement and has braopkets 15.6 lo

l0Y are .coupled piston rods |58 ofc. piston and cylinder providing the power device 38. f yThere are two power devices 88 situated along `lthe length of the stringers 36 .though more may .be used if necessary, and all are connected by the conduits |-34 and |36 to a pump and cycling unit |38 similar to Fig. 15. Both power devices 38 are mounted on a rigid ,supporting structure |62 beneath the stairway, and .all of the conduits |34 .are joined to a common pipe .orpassage leading to one sidel of the Icycling switch A'while the other side of the 'cycling .switch similarly connects tothe conduits |38 .of all the power devices so that the piston and cylinder Adevices will be actuated equally and in the .same direction at l.the same time.

-tl-ie stairway lis Vmotion the even bored steps are `raised and lowered the distance between levels of odlooent .steps es molested ,et Af Steps, 2,4, i. s. .1.0. .4;2. 1.4 `and i6 .move .from the solidline position in Fla 4 to .the level of .ille .difesi steps molested byfdashed lines el a, 5 j, s kll, le, .is epd Ll1 respectively. opviollslv the eleetrieel moons for driving the .move able ,structure .of Fie 15 mov also ibe used for driving theveriieel sans of steps, and when oon.- trollesi by the switel-l ll. makes ,for sterline .and stopping of the stairs et elly .point lll 46. :17 and :1.8 :there is shown mecha: nism =for ind-ividuallyactuating steps in a progressive fashion. VMounted on -the horizontal -faces |54 .of :the .stringers 36 there are guide posts |66 capped :by head `members |68 lto which bellows Walls H8 are attached for `connecting the tread |12 .and .making a couapsibie .and expaneible chamber H11-.whose sides Vare reinforced by aboxlike structure inducing the members |16 arid 1a that are capable pf .telesopmg 'over the head member its/Traversing vtheginde-posts |66 there arerigid tubes |80 and |82 secured at the upper `end t avalvebox '|l84 secured tothe undersideof the'tread member |12, thereby extending vertically k.through the bellows chamber '|14 and slidable vthrough `the head members |39. it the lowerendlof'the pipes |90 and |82 there are fles;- ible pipe erboso-connections |86 and |88 that join ffluid-pressure-lines |80, |92 leading'to land from a sfluid :pum-p @[94 driven ,by a motor "60. Aniexpansion chamber or fluid accumulator y|36y may :be incorporated inlthe vpump output line to i smoothput the operation o fthe mechanism.

mheiine l| so isasucuop une andpopnects'with the vpipe |88 -of ail step lifting motors, rfor confnecting with-theintake'fto the pump |94, whilethe line #|92 `is -a wpressure line V4and' connects with the pipes |482 "of .all step lifting motors 'for connesting withcheoutpufside ofthe pumpl," when the `dri-ving motor 60 is venergized the pump 'l 9,4 tends to draw .the fluid ymedium out ofthe pipe HBL-and its .connecting cavities and force the medium into -thefpipe '|92 vandits cavities. The rise and loweringof the steps is controlled by thevvalvebox y| shown in enlarged detail in Fig. 1a. wahmrhe valve pox m which is @pedir mechamber .1,14 thereis a-.vawe ybody |191 x'ed to theunderside of the tread member A|12 and provides open ports L|98 andZBO-conriectifig tlebore of the-body luit with `the chamber m. v pair of ,con-trol v ports '.2293 ,and ,-.204 connect thebore of thezbody-'withfpassages -2'06 and M18-that in turn connect wahren@ pipes l-s and Im2 respectively. @9091 :lflve ,2,10 is movable alongthe bore of lill? @Ny by@ :,StemfZzl 2,extending-upvvardthrough tige-:treed |12to :engagea falsetread 2| 4 hinged to `f 1 =on t ldgeof :the -real tread. 4The lvalve 2| 0 is thrust upward by a spring 216 so that a valving land 2|8 normally closes off the control port 204 to the pressure line |82. An enlargement 2|9 of the stem 2|2 acts as a stop for the valve 2|0 so that in the spring pressed or normal position the control port 202 is open to the suction line |80.

The drain ports |98 and 200 are open to the bore of the body and to the interior of the valve box |04 which is open through the holes 220 to the bellows chamber 14. The control valve is actuated by stepping upon the false tread 2|4' which depresses the valve 2|0 to close the suction port 202 and open the pressure port 204 to the open port |98. In this depressed position oi the valve, the ilow of fluid medium from the pump |94 fills the chamber |14 and expands the bellows which raises the step to the upper limit. In Fig. 17, steps number and 24 are shown in the rest or down position ready to be raised by the pressure from the pump |94, and the step number 22 is shown in the projected or raised position level with the step 24. When the foot is removed from the false step, the valve returns to the up position closing the pressure port 204 and opening the suction port 202 to the port 200 so that the chamber |14 is now connected to the intake of the pump |94, which withdraws the fluid medium from the chamber |14 for collapsing the bellows and lowering the step to the rest position. Thus, a person may be transported from a lower level to a higher level by successively stepping on the tread of the next step, after being raised to that level by the ilow of uid pressure into the corresponding chamber incident to opening of the pressure port Iby shifting the load onto the lowered step.

The progressively actuated steps with an adaptation to the transporting of inanimate objects, such as a lug box, crate or parcel, is illustrated in Fig. 19 where the step stringers 36 similarly support a number of steps for vertical guided movement by means similar to that shown in Figs. 16 to 18. The tread of each step in Fig. 19 is not horizontal but slants downward therefrom with respect to the tread nosing, and mounted in the tread of each step there are a plurality of rollers 222 arranged parallel with the tread nosing. A tread lever 224 is placed near the back edge of step, and normally projects above the rollers 222, but when depressed will actuate the valve 2|0 to admit fluid pressure to the corresponding bellows chamber |14. When this type of moving stairway is in operation, step number 2 will be in the rest position shown in dotted lines where it is level with the floor The article 225 to be transported to the level 28 is placed on the roller tread of step number` 2 which depresses the valve 2|0 as explained with respect to Figs. 16 to 18. Fluid pressure raises the step number 2 with its load to the level oi' step number 4 as shown in Fig. 19, the load 226 then being free to coast down the incline of the slanting treads from step 2 onto the tread of step 4. In doing so, the tread lever 224 of step 2 is released and the tread lever of step 4 is depressed. The chamber |14 of step 2 being connected to pump intake is now collapsed with accompanying descent of the step, while the chamber |14 of step 4 is expanded, since it is connected to the pump output line. The step 4 with its load 226 is thereby raised to the level of step 6 and so on until the load reaches the level of iioor 28 where it is taken away by an attendant or a conveyor. At each step level the load coasts on the rollers 222 toward the back of the step tread until it bumps against the riser of the next step. As the step carrying the load rises clear of the riser on the adjacent step the load coasts down the incline of the tread onto the tread of the next step, and in doing so releases the control valve for one step and actuates the control valve for the next step, thus providing a progressive movement, step by step, from one level to another.

While we have, for the sake of clearness and in order to disclose our invention so that the same can be readily understood, described and illustrated speciilc devices and arrangements, we desire to have it understood that this invention is not limited to the specific means disclosed but may be embodied in other ways that will suggest themselves, in view of this broad disclosure, to persons skilled in the art.

Having thus described the invention, what we claim and desire to secure by Letters Patent is:

1. Transporting equipment for moving a person from one iioor level to another iioor level, comprising in combination, a reciprocating mechanism extending between iioor levels, a xed mechanism extending between the iloor levels parallel with the reciprocating mechanism, both cf said mechanisms having equally spaced foot rests extending throughout the length of the mechanisms, power means for actuating the re ciprocating mechanism so that its foot rests move from one foot rest level to another of the iixed mechanisms, and then move back to the level of the rst foot rest, and control means for the power means whereby a person may start and stop the reciprocating mechanism at any point along the extent of the mechanisms.

2. In transporting equipment for moving persons from one level to another without the person exerting muscular effort other than to wall: on the level, the combination comprising, a fixed string of steps extending from one level to an adjacent level, a second string of steps beside the iixed string of steps and normally having its steps on the same level with the steps of the iixed string but movable to the level of an adjacent step, means under control of the person to be transported for moving the second string of steps throughout the spacing of two adjacent steps of the iixed string, and means under control of the moving string of steps for stopping the movement of the said second string at the normal position wherein the steps of the movable string will come to rest level with the steps of the xed string.

3. A stairway for transporting a person from one floor level to another comprising in combination. a string of steps mounted on stringers and providing a plurality of steps of uniform tread and riser aggregating the distance between levels, spaced foot rests fixed along the extent of steps, guide rails secured to the stringers, rollers cooperating with each guide rail and permitting the string of steps to slide on an incline toward and away from each floor level, actuating means coupled to the stringers of the steps for reciprocating the steps between the levels of two adjacent treads, power means for driving the aotuating means, and a manually actuated means extending along the string of steps for controlling the operation of the power means.

4. A stairway for transporting a person from one floor level to another comprising in combination, a string of steps mounted on stringers and providing a plurality of steps of uniform tread and riser aggregating the distance between levels, spaced foot rests fixed along the extent of steps, guide rails secured to the stringers, rollers cooperating With each guide rail for confining the string of steps to slide on an incline toward and away from each floor level, actuating means coupled to the stringers of the steps for reciprocating the steps between the levels of two adjacent treads, power means for driving the actuating means, and a manually actuated means for controlling the operation of the power means and power interrupting means in parallel with the manually actuated means and actuatable at any point along the step reciprocation for stopping the steps on a level with the foot rests when the manually actuated mean-s has cut off operation of the power means.

5. The combination set/forth in claim 3, wherein the manually actuated means includes a manually operable member adapted to be moved by a person at any position along the extent of the string of steps, a movable switch support adapted to be moved by said manually operable member, and a power switch carried by the movable support and which when in one position of the movable support is operated by the moving string of steps to interrupt the power means only when the steps are level with the foot rests.

6. In an oscillating stairs for transporting persons between oor levels, the combination comprising, a set of immovable steps extending between said floor levels, a set of movable steps rigidly connected together and slidably mounted for movement as a unit along the extent of the set of immovable steps, power means for reciproeating the movable set of steps between limits coincident with the level of successive steps of the immovable set of steps, and manual control means for the power means including an electric switch having a circuit opening member movable into and out of the path of movement of the movable set of steps, and means locating the switch for engagement of the circuit opening member only at one end of the stair reciprocation whereby the movable steps will always come to rest at the level of the immovable steps.

7. In an oscillating stairs, the combination comprising, a movable set of steps having risers and treads for supporting a load thereon, power means for oscillating the steps along a path of movement having limits coincident with spaced tread levels, control means for starting and stopping the power means, and positioning means cooperable with the control means for stopping the set of steps at one of the said limits of oscillation whereby the steps will always be arrested with the treads iiush with' one of said spaced tread levels.

ALEXANDER MICHAEL GEORGIEV. LEONARD J. RAWSON.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 807,564 Lorillard Dec. 19, 1905 2,341,463 Maytham Feb. 8, 1944 2,534,110 Dice Dec. 12, 1950 FOREIGN PATENTS Number Country Date 11,482 Great Britain July 1'7, 1902 13,210 Great Britain Nov. 3, 1910 

